Wave movements in the sea and in large inland lakes constitute a potential source of energy that has scarcely been exploited so far. However various suggestions have been made to use the vertical movements of the sea for producing electrical power in a generator. Since a point on the sea surface makes a reciprocating vertical movement it is suitable to use a linear generator to produce the electric power.
WO 03/058055 discloses such a wave power unit where the moving part of the generator, i.e. the part that corresponds to the rotor in a rotating generator and in the present application called translator, reciprocates in relation to the stator of the generator. In that disclosure the stator is anchored in the sea bed. The translator is by flexible connection means, such as a wire, cable or a chain connected to a body floating on the sea.
The stator and the translator of the generator are encapsulated in a water-tight housing. Since the generator is located closed to or at the sea bottom service and maintenance thereof is complicated. This requires that the generator is very reliable in operation. Furthermore, in order to provide a competitive energy source in a commercial scale, it is important to minimize the costs for manufacturing and assembling the generator. The requirements on high reliability and low manufacturing costs imply an optimized design and construction of the generator